Participants in this double-blind study will be paired according to IQ and baseline symptom severity. One member of each pair will be randomly assigned to training exercises that use TCT. The other will be assigned to a control intervention, which will involve commercially available computer games. All participants will complete exercises with their assigned intervention for 1 hour per day, 5 days per week, until 90 hours of training has been accumulated. Neuroimaging will be performed on a subgroup of participants to examine changes in brain activation patterns in response to the cognitive training. Upon study completion and at the 6-month follow up visit, participants will be assessed for improvement in the following areas: cognitive performance; symptom profile; quality of life; and social cue recognition.